TUNNEL`S GEYSER EFFECT STILL PUZZLING

Rob KarwathCHICAGO TRIBUNE

Dolores Crane swears she`ll never stop her car over a manhole cover again.

About 8 a.m. on Oct. 3, as the 61-year-old Bridgeport woman was waiting at a traffic light at Jefferson and Monroe Streets on her way to work, she felt her 1981 Pontiac Bonneville rise slightly. Then the car`s rear end jerked up at a 45-degree angle from the street, and foul-smelling water rushed in around her.

''Suddenly I felt like I was in a little dinghy in the middle of the ocean,'' Crane said.

Unwittingly, Crane had stopped on the grill of a ventilation shaft for the Metropolitan Sanitary District`s Deep Tunnel. That morning, the huge tunnel--filled ''up to the gunnels'' with runoff from heavy rains, according to the sanitary district`s assistant chief engineer--blew its top and spouted a 30-foot geyser of water under Crane`s car.

Similar spouts were reported that morning at two tunnel shafts in Evanston, said Bill Macaitis, the assistant chief engineer. No one was injured by the Evanston geysers, which spouted along the North Branch of the Chicago River at Central Street and at Isabella Street. But the powerful surges blew off the metal grills welded over the shafts and startled commuters walking to the nearby Central elevated stop.

In the Loop, however, Crane was unlucky enough to be stopped over the eight-foot-round grill when the geyser blew.

''I was only two blocks from my office,'' she said. ''All of a sudden, I thought my car was up, then down, then up. The surge was unbelievable. I didn`t know what was hitting me.''

A passer-by, Jeffrey Francik, a public opinion researcher at the University of Illinois at Chicago, saw what was happening and rushed to aid Crane, who couldn`t move from the car. Another passer-by, Jack Fehlandt, a bank systems analyst and the mayor of Streamwood, also stopped to help.

''Her eyes were the size of golf balls,'' Francik said. ''I ran over, opened the door and pulled her out of the car. She was so shaken up, she was like a limp dishrag.''

All three of the geysers lasted less than two minutes, witnesses said. Then they disappeared into the shafts.

Macaitis said the blasts were ''an extreme situation'' caused by the week`s heavy rains, which also flooded parts of Lake, Cook and McHenry counties. The morning the geysers spouted, sanitary district officials judged the billion-gallon capacity Deep Tunnel to be full and decided to release 53 million gallons of sewage and rainwater into Lake Michigan at Wilmette Harbor. Macaitis said the geysers ''shouldn`t have happened. We`re looking into why they happened.'' He said that the two Evanston shafts had spouted about a year ago when the Deep Tunnel first opened, but that sanitary district engineers thought they had solved the problem.

The geysers were caused by high pressure in the tunnel when it filled to capacity, Sanitary District Commissioner Aurelia Pucinski said Thursday. Pucinski, who supervises Deep Tunnel operations as head of the district`s flood-control committee, said district engineers are working to prevent the problem by allowing a layer of air to remain over the sewer water in the tunnel at all times, preventing pressure from building up.

According to Leo DiVita, chief engineer for the MSD, there are ''about 100'' such grates in the Chicago area.

As for Crane, her car now sits in a junkyard, its roof and windshield smashed by the sewer water as it plummeted back to the ground. The water also smashed the roof of another car parked nearby.

Crane escaped with minor cuts on her hand and forehead from the cracked windshield. But two weeks after the freak accident she said she remains ''a bundle of nerves.''

''I almost drowned in my own car. That`s what makes me so upset,'' she said.

Francik and Fehlandt said they are upset about what they perceive as the lack of concern shown by sanitary district officials after the accident.

''They said they would call me back, and to date nobody has,'' said Fehlandt, who also wrote a letter explaining what had happened and complaining that the shafts are dangerous. ''I`m wondering, how many other vents are there, and how many people are exposed to them?''

Pucinski said commissioners have told the district`s law department to see that Crane and the owner of the other car damaged by the Loop geyser are reimbursed within two weeks. She also said the district is considering ways to warn motorists and pedestrians about the possibility of geysers.

''We may post signs around the shafts warning that in storms there is a possibility of some activity and that people shouldn`t park around there,''

she said. ''We`re also going to see about contacting local police departments to see whether during storms they could post police cars with flashing lights there or possibly barricades.''

Meanwhile, Crane has hired a lawyer and expects the sanitary district to pay for her medical bills and a new car. But some of the damage can`t be undone, such as her newfound fears while driving. Also, the sewer water ruined a purse, a folder of important papers and washed away her glasses.